Quick question

[Naraic]

I do large 200 liter batches, normally using LME and a "mini" mash of about 16kg grain in a keggle. Now what I am wondering is if i could mash in a BIAB bag in my large kettle with about 240 liters of water or dose the vessel need to be smaller to get decent efficiency?
What I am thinking will happen is efficiency will be really low akin to steeping grain efficiency which my online brew calculator estimates as 35%

Would it make any difference to mash with the LME in the mix or am I in an loosing enzyme race?
Thanks lads

 

[billl]

I haven't seen any data on mashing that thin. That's about 3 times as much water as you normally would use even in no sparge brewing. You can try it, but you'll need to watch the PH and you'll probably get mediocre conversion.


If you are just looking to cut out a vessel, you can mash in a bag in the kettle with just a lower volume of water. Once the mash is done, pull the bag, sparge with some extra water, and fill the kettle the rest of the way.

Adding extract definitely won't help in conversion.

 

[Naraic]

Thats how I mash with bag in kettle. I wonder if I mashed in kettle collected runoff then pulled the bag and dunk it in main kettle? Probably losing a lot of efficency along the way? (I need all I can get)

 

[Gnomebrewer]

If you are thinking about using 16Kg of grain in 200L of water, you'll get very slow conversion (not enough random collisions between enzymes and starch molecules). You could start using grain entirely (instead of LME) as a way to save a LOT of $$$. You'd need about 40Kg of grain for a 200L batch at 5% ABV, which would weigh about 100Kg coming out of the large kettle, so you'd need a pulley system to lift it out. The cost of grain vs. the cost of LME would quickly pay for a pulley and large grain bag! You should be able to get to 80% efficiency quite easily with a quick sparge/rinse through the grain bag while it hangs above the kettle, and a good squeeze of the bag.